Circular digger



April 15, 1958 E. J. KEMPER 2,330,790

GIRCULARbIGGER Filed July 18, 1955 3 Sheets-Sheet 1 Edmund J kemper INVENTOR.

April 15, 1958 E. J. KEMPER CIRCULAR DIGGER 3 Sheets-Sheet 2 Filed July 18, 1955 Edmund J Kemper INVENTOR.

2 all CIRCULAR BIGGER Edmund J. Kemper, Louisville, Ky.

Application July 18, 1955, Serial No. 522,652

3 Claims. (Cl. 255-3) This invention relates to new and useful improvements in digging apparatus, and more specifically to an improved circular digger for digging circular cross-sectional holes in the earth.

The primary object of this invention is to provide an improved circular digger which includes an anchor shaft adapted to be anchored in the earth against rotation and on which a blade assembly is mounted for rotation, the anchor shaft providing a suitable support for the entire drilling apparatus.

Another object of this invention is to provide an improved circular digger of the type which incorporates an anchor shaft which is intended to be anchored in the ground against rotation and which has rotatably mounted thereon a blade assembly, the blade assembly being pro vided with suitable drive means, and such drive means being provided wtih means for hammering the anchor shaft progressively into the ground as digging progresses.

Still another object of this invention is to provide an improved circular digger which is so constructed whereby it is of a relatively simple and compact construction so as to be economically feasible in its manufacture.

A further object of this invention is to provide an improved blade assembly for a circular digger, the blade as sembly including a generally saucer-shaped member having openings in the bottom thereof, the openings-having blades as borders to facilitate the digging from the bottom, the saucer-shaped member also being provided with upwardly extending blades for shaping the hole being dug.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a perspective view of the circular digger which is the subject of this inventionand shows the same suspended preparatory to the use thereof in a digging operation;

Figure 2 is an enlarged transverse horizontal sectional view taken substantially upon the plane indicated by the section line 22 of Figure 1 and shows the Specific details of the blade assembly of the circular digger;

Figure 3 is an enlarged fragmentary transverse horizontal sectional View taken substantially upon the plane indicated by the section line 3-3 of Figure 1 and shows the manner in which an anchor blade is detachably secured to the anchor shaft of the circular digger;

Figure 4 is an enlarged elevational view of the circular digger with portions thereof being broken away and shown in section for purposes of clarity;

Figure 5 is an enlarged fragmentary elevational view of the circular digger taken at right angles to the view of Figure 4 with parts being shown in section along a section line 55 of Figure 4 and shows the further details of the drive mechanism for the blade assembly, an intermediate portion of the circular digger being broken away;

nited States Patent 6 "ice Figure 6 is an enlarged fragmentary vertical sectional view taken substantially upon the plane indicated by the section line 6-6 of Figure 5 and shows more specifically the details of the circular digger including the means for rotating the blade assembly and the means for driving or hammering the anchor shaft;

Figure 7 is an enlarged fragmentary vertical sectional view taken substantially upon the plane indicated by the section line 7-7 of Figure 6 and shows the means for driving the anchor shaft; and

Figure 8 is an enlarged fragmentary vertical sectional view taken substantialy upon a plane indicated by the section line 88 of Figure 4 and shows the details at the lower end of a drive shaft for the blade assembly.

Referring now to the drawings in detail, it will be seen that the circular digger, which is the subject of this invention, is referred to in general by the reference numeral 10. The primary part of the circular digger is a gear housing which is referred to in general by the reference numeral 12.

Referring now to Figure 6 in particular, it will be seen that the gear housing 12 is preferably in the form of a portion of a vehicle rear axle housing and includes a cylindrical banjo 14. Extending downwardly from the banjo 14 and secured thereto by suitable fasteners 16 is an elongated tubular member 18. Secured to the upper part of the banjo A by suitable fasteners 2% is a cover 22 which is in the form of a part of a rear axle housing which has been cut off short.

The tubular member 18, which is in the form of a rear axle housing half, is provided at the upper end portion thereof with a bearing 24. A similar bearing 26 is disposed in the rear axle housing half 22. The bearings 24 and 26 are in alignment and have journaled therein a tubular drive shaft 28. The lower portion of the tubular drive shaft 28 is journaled in a bearing 3% carried by the lower part of the tubular member 13. The bearing 30 is retained in place by a ring 32 and the lower end of the member i8 is sealed by a suitable sealing ring 34 held in place by an adjustable nut assembly 36.

In order that the drive shaft 22% may be rotated, there is secured thereto a ring gear The ring gear 38 has meshed therewith a drive pinion 44 which is carried by a drive shaft 42. The drive shaft 42 is suitably journaled in a bearing 44 carried by the banjo 14.

Removably secured to the lower end of the drive shaft 28 is an extension as. The extension 46 extends downwardly and has secured to the lower end thereof by welding 43 a collar 5b. The collar 50 is a part of a blade assembly, which is referred to in general by the reference numeral 52.

The blade assembly 52 includes a saucer-shaped member 54 including a bottom 56 and upwardly and outwardly extending wall portion 58. As is best illustrated in Figure 2, the bottom 56 and the wall portion are provided with diametrically opposite openings of An edge of each of the openings 6i) is bounded by a scraper blade 62 which depends slightly below the main portion of the saucer-shaped member 54 to urge earth upwardly through the openings 60. In order that the saucer-shaped member 54 will freely pass down through the earth at the same time may be easily removed from a hole being bored, such as the hole 64, there are provided auxiliary blades 66. The blades '66 are of the spring type are secured to the wall 58. The blades 66 extend upwardly and outwardly of the saucer-shaped member 54- and form the finished wall surface of the hole 64'.

As is best illustrated in Figure 8, the drive shaft extension 46 is tubular, like the drive shaft 28. Disposed in the lower part of the drive shaft extension as is a bearing 68. The bearing 68 has journaled therein an anchor shaft 70. The lower end of the drive shaft exgaged therein and positioned around the anchor shaft 7d.

The anchor shaft extends downwardly below the blade assembly 52 and terminates in a keyed lower portion 74. Removably keyed on the lower portion 74 is an anchor blade 76. The anchor blade '76 is retained in place by means of a setscrew 73 which extends through a tubular portion 8% of the anchor blade 76, the tubular portion 89 being internally splined to engage over the keyed portion '74- of the anchor shaft 7b. The anchor blade 76 also includes a centrally located, downwardly projecting point 82.

Carried by the banjo 14 and disposed between the lower part of the cover 22 and the banjo 14, as is best illustrated in Figure 6, is a mounting plate 84'. The mounting plate 84 is generally rectangular in outline and in retained in place by the fasteners 20.

As is best illustrated in Figure 5, the anchor plate 84 has extending upwardly therefrom on opposite sides of the housing 12 a pair of X-shaped frame members 86. Each of the frame members 86 is provided with an intermediate hub portion 88, the hub portions 88 being transversely aligned. The X-frames 86 are in spaced parallel relation, as is best illustrated in Figure 6.

Extending between the upper ends of the )(-frames 86 and secured thereto is an electric motor 90 or any other suitable power source. The electric motor 90 includes an armature shaft 92 which has mounted on the outer end thereof a drive gear 94.

The hub portions of the X-frames 86 are provided with suitable bearings 96. The bearings 96 have journaled therein a countershaft 98. The countershaft 98 has mounted thereon for rotation therewith an enlarged drive gear 10%. The drive gear 1% is meshed with the gear 94 and driven thereby. The drive gear 100 is meshed with the gear Hi2 carried by an extending portion of the drive shaft 42. Thus, the tubular drive shaft 28 may be driven by the electric motor 9%) at a reduced speed.

Referring once again to Figure 6 in particular, it will be seen that the cover 22 is provided with a tubular extension 104. The extension 104 is secured to the cover 22 by suitable fasteners 106. Overlying the extension 104 is a cover plate 108 which is secured in place by suitable fasteners 110.

Formed in the cover plate 198 in the central part thereof is a rectangular or square opening 112. Mounted in the opening 112 for guided vertical movement is a tappet 114. The upper end of the tappet 114 is provided with a follower U6. The follower 116 is aligned with a cam 118 formed on the countershaft- 98. follower 116 is retained in engagement with either the countershaft Q8 or the cam 118 by means of a coil spring 120 disposed between the follower 116 and the cover plate 108.

The upper end of the tubular drive shaft 28 is open and it is provided with an annular guide ring or bushing 122. The bushing 122 has extending upwardly therethrough the upper end portion of the anchor shaft 79. The anchor shaft 76 is disposed immediately below the tappet 114 and is engaged by the tappet 114 when driven downwardly by the cam 118. Thus, the tappet 114 continues to hammer the anchor shaft 7!) downwardly so that the anchor blade 76 thereof is continuously driven into the ground and rotation of the anchor shaft 70 prevented.

Secured to the plate 84 and overlying the power source 90 as Well as the gears of the gear train is a cover 124. A similar cover 126 is secured to the underside of the plate 84. The cover 126 has a central opening 128 which is slid up over the member 18 of the housing Extending outwardly from the plate 84, the cover .124. and the cover 126 are aligned ears 130, 132 and 134, ro

spectively. The ears 132 and 134 serve to secure the cov- '4 136. The eye bolts 136 have engaged therethrough looped portions 138 of lifting cables 140.

In the operation of the present invention, the circular digger 10 is suspended by means of a lifting line 142 which is connected to the lifting cables 140 by means of a swivel 144. The lifting line 142 is carried by a crane or other similar lifting device so that the circular digger 10 may be raised and lowered as desired. The circular digger 10 is positioned in the desired spot and the point 82 is centered. Then, the digger 10 is lowered so that the weight thereof will force the anchor blade 76 into the ground and the blade assembly 52 will rest upon the ground. Then, the power unit 9% is energized with the result that the blade assembly 52 is rotated to scoop the earth up through the bottom of the saucer-shaped pan or member 54. At the same time, the anchor shaft 70 is being continuously driven downwardly so as to provide a suitable support for the rest of the circular digger 10 at all times. After the saucer-shaped member or pan 54 has been filled with earth, the entire digger 10 is then elevated and the earth dumped upon the ground. It is then lowered back into place with the anchor blade 76 assuming its original position. Inasmuch as the blades 66 are formed of spring metal, they will form a wall of the hole 64 of such a diameter so that the saucer-shaped member 54 may be easily removed from the hole 64 being drilled. The process is repeated until such time as the desired depth hole 64 has been dug. Then, the entire circular digger 10 may be transported to the next position.

While the invention has been illustrated and described as being driven by a motor, the invention is not intended to be so limited. If desired, a suitable hand crank can be utilized.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A circular digger comprising a vertical anchor shaft, means on said anchor shaft for engaging material being drilled to prevent rotation of said anchor shaft, 2 blade assembly mounted on said anchor shaft for rotation thereabout, and drive means connected to said blade assembly for rotating the same, said drive means including a gear housing, said blade assembly including a tubular drive shaft telescoped over said anchor shaft, said drive shaft being rotatably journaled in said gear housing, gear means in said gear housing connected to said drive shaft, a power unit mounted on said gear housing and drivingly connected to said gear means.

2. A circular digger comprising a vertical anchor shaft, means on said anchor shaft for engaging material being drilled to prevent rotation of said anchor shaft, a blade assembly mounted on said anchor shaft for rotation thereabout, and drive means connected to said blade assembly for rotating the same, said drive means including a gear housing, said blade assembly including a tubular drive shaft telescoped over said anchor shaft, said drive shaft being rotatably journaled in said gear housing, gear means in said gear housing connected to said drive shaft. .1 power unit mounted on said gear housing and drivingly connected to said gear means, said anchor shaft extending through said drive shaft, means including a cam driven by said power unit engageable with said anchor shaft for effecting longitudinal driving thereof.

3. A circular digger comprising a vertical anchor shaft, means on said anchor shaft for engaging material being drilled to prevent rotation of said anchor shaft, a blade assembly mounted on said anchor shaft for rotation thereabout, and drive means connected to said blade assembly for rotating the same, said drive means including a gear housing, said blade assembly including a tubular drive shaft telescoped over said anchor shaft, said drive shaft being rotatably journaled in said gear housing, gear means in said gear housing connected to said drive shaft, 2 power unit mounted on said gear housing and drivingly connected to said gear means, said anchor shaft extending through said drive shaft, means including a cam driven by said power unit engageable with said anchor shaft for effecting longitudinal driving thereof, a gear train between said power unit and said gear means, said gear train including a countershaft, said cam being carried by said countershaft.

References Cited in the file of this patent UNITED STATES PATENTS Eagleston 1- July 1, Robinson Jan. 12, Lindsay June 1, Shell Mar. 28, Casey Jan. 6, Sullivan Feb. 12, Howard Sept. 15, Gooder Aug. 31, Snyder Apr. 17,

FOREIGN PATENTS Great Britain Oct. 8, 

